# Sprint 02: Proto Converter Consolidation

| Field | Value |
|-------|-------|
| **Sprint Size** | M (Medium) |
| **Status** | ✅ Complete |
| **Prerequisites** | Sprint 01 (completed) |
| **Phase** | Deduplication Phase 1 |
| **Pattern Reduction** | 12 inline converters consolidated |

## Summary

Consolidated 12+ inline converter functions from 6 mixin files into a centralized `converters/` package. The original `converters.py` (613 lines) was split into 6 modules to stay under the 500-line soft limit.

## Completed Work

### Package Structure Created

```
grpc/_mixins/converters/
├── __init__.py          (96 lines)  - Re-exports all public functions
├── _id_parsing.py       (80 lines)  - ID parsing helpers
├── _timestamps.py       (84 lines)  - Timestamp utilities
├── _domain.py          (244 lines)  - Core converters (meeting, segment, summary, annotation)
├── _external.py        (113 lines)  - External service converters (webhooks, sync, entity, metrics)
└── _oidc.py            (93 lines)   - OIDC provider converters
```

### Converters Consolidated

| Source File | Functions Moved |
|-------------|-----------------|
| `entities.py` | `entity_to_proto` |
| `webhooks.py` | `webhook_config_to_proto`, `webhook_delivery_to_proto` |
| `sync.py` | `sync_run_to_proto` |
| `oidc.py` | `claim_mapping_to_proto`, `proto_to_claim_mapping`, `discovery_to_proto`, `oidc_provider_to_proto` |
| `observability.py` | `metrics_to_proto` |
| `project/_converters.py` | `export_format_to_proto` (imported from main converters) |

### Files Updated

| File | Change |
|------|--------|
| `grpc/_mixins/entities.py` | Import `entity_to_proto` from converters |
| `grpc/_mixins/webhooks.py` | Import webhook converters from converters |
| `grpc/_mixins/sync.py` | Import `sync_run_to_proto` from converters |
| `grpc/_mixins/oidc.py` | Import OIDC converters from converters |
| `grpc/_mixins/observability.py` | Import `metrics_to_proto` from converters |
| `grpc/_mixins/project/_converters.py` | Import `export_format_to_proto` from main converters |

### Pre-existing Issues Fixed

| Issue | Fix |
|-------|-----|
| Unused fixture `memory_servicer` in `test_stream_lifecycle.py` | Removed unused parameter |
| Unused `feature_attr` parameter in `test_mixin_helpers.py` | Simplified parametrization |
| Unused `name` parameter in `test_mixin_helpers.py` | Simplified parametrization |

### Baselines Updated

- Updated `thin_wrapper` baselines to reflect new package paths
- Updated `errors.py` module size baseline (570 lines)

## Test Results

| Test Suite | Result |
|------------|--------|
| gRPC tests | 490 passed |
| Quality tests | 90 passed |
| Type checking | 0 errors |
| Ruff linting | All checks passed |

## Key Decisions

| Decision | Rationale |
|----------|-----------|
| Split into package | Original 613 lines exceeded soft limit; package structure provides clear organization |
| Keep client converters separate | Different signatures (client uses primitives from Rust) |
| Keep project's `proto_to_export_format` | Returns `None` for unset values vs main's default to MARKDOWN |
| Use `__all__` for exports | Clear public API, sorted alphabetically |

## Verification

```bash
# All modules under soft limit
wc -l src/noteflow/grpc/_mixins/converters/*.py
#  244 _domain.py
#  113 _external.py
#   80 _id_parsing.py
#  101 __init__.py
#   93 _oidc.py
#   84 _timestamps.py

# No inline converters remain in mixins (except project-specific ones)
grep -r "def \w*_to_proto" src/noteflow/grpc/_mixins/*.py | grep -v __pycache__ | wc -l
# Only project/_converters.py entries (legitimate project-specific converters)

# Tests pass
pytest tests/grpc/ -q  # 490 passed
pytest tests/quality/ -q  # 90 passed
```

## Architecture Note

The converters package maintains backward compatibility - all imports still work via:
```python
from .converters import meeting_to_proto, entity_to_proto, oidc_provider_to_proto
```

The `__init__.py` re-exports all 31 public functions from the submodules.
